X90 level heterogeneous structure pipeline steel plate for longitudinal welded pipe and manufacturing method of pipeline steel plate

Abstract

The invention relates to an X90 level heterogeneous structure pipeline steel plate for a longitudinal welded pipe and a manufacturing method of the pipeline steel plate. According to the research and practice of the physical metallurgy principle, recrystallization rule and phase change rule of materials, innovative X90 level high-strength pipeline steel is invented. The pipeline steel has a heterogeneous microstructure, and the implementability of the process is researched, so that perfect combination of high strength, high toughness and high plasticity is realized. The X90 level pipeline steel plate used for longitudinal submerged arc welding refers to a pipeline steel plate which integrates the high strength, high toughness and high plasticity into a whole, wherein the yield strength (RP 0.2) is more than or equal to 555MPa, the tensile strength (Rm) is more than or equal to 695MPa, the yield ratio (RP 0.2 / Rm) is less than or equal to 0.75, the uniform elongation (UEL) is more than or equal to 11 percent, KV2 at the temperature of 20 DEG C below zero is more than or equal to 300J, and DWTT at the temperature of 15 DEG C below zero is more than or equal to 85 percent.

Description

technical field

[0001] The invention belongs to the technical field of high-strength pipeline steel manufacturing, and relates to an X90 grade multi-phase structure pipeline steel plate for oil and gas transportation straight seam welded pipes and a manufacturing method thereof. Background technique

[0002] Since the 21st century, with the continuous demand for energy such as oil and natural gas due to economic development at home and abroad, it is necessary to build a large number of long-distance transmission pipelines. Following the construction of the first and second pipeline projects of the West-to-East Gas Pipeline, the third pipeline of my country's West-to-East Gas Pipeline has started construction, and the fourth, fifth, and even seventh and eighth pipelines are under planning and research. In order to reduce construction costs, further improving the transmission efficiency of domestic natural gas pipelines has become the development direction of the natural gas p...

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